• SQLiteDatabase


    package com.demo.database;
    
    import java.io.File;
    
    import android.app.Activity;   
    import android.app.AlertDialog;   
    import android.content.ContentValues;   
    import android.content.DialogInterface;   
    import android.database.Cursor;   
    import android.database.sqlite.SQLiteDatabase;   
    import android.database.sqlite.SQLiteStatement;
    import android.os.Bundle;   
    import android.widget.ListAdapter;   
    import android.widget.ListView;   
    import android.widget.SimpleCursorAdapter;   
    import android.widget.TextView;
      
    public class main extends Activity {   
        /** Called when the activity is first created. */  
        private ListView lv = null;   
        private TextView tv=null;
        private SQLiteDatabase mSQLiteDatabase = null;  
        private SQLiteStatement st=null;
        private static final String DATABASE_NAME = "Test.db";   
        private static final String TABLE_NAME = "table_test";   
        private static final String COLUMN_ID = "_id";// INTEGER PRIMARY KEY   
        private static final String COLUMN_NAME = "name";// TEXT   
        private static final String COLUMN_AGE = "age";// INTEGER   
        private static final String CREATE_TABLE = "CREATE TABLE IF NOT EXISTS "  
                + TABLE_NAME + " (" + COLUMN_ID + " INTEGER PRIMARY KEY,"  
                + COLUMN_NAME + " TEXT," + COLUMN_AGE + " INTEGER)";   
    	private File path = new File("/sdcard/myfile");// 创建目录
    	private File f = new File("/sdcard/myfile/test.db");// 创建文件
    
        @Override  
        public void onCreate(Bundle savedInstanceState) {   
            super.onCreate(savedInstanceState);   
            setContentView(R.layout.main);   
            lv = (ListView) this.findViewById(R.id.ListView01);   
            tv = (TextView) this.findViewById(R.id.counttip); 
            try {   
               // mSQLiteDatabase = this.openOrCreateDatabase(DATABASE_NAME,   
               //         Activity.MODE_PRIVATE, null);   
            	if (!path.exists()) {// 目录存在返回false
        			path.mkdirs();// 创建一个目录
        		}
        		if (!f.exists())f.createNewFile();//创建文件  
        		mSQLiteDatabase=SQLiteDatabase.openOrCreateDatabase(f, null); 
    
            } catch (Exception ex) {   
                this.ShowDialog("打开或者创建数据库异常:" + ex.getMessage());   
            }   
            try {   
                mSQLiteDatabase.execSQL(CREATE_TABLE);  
                String str = "INSERT INTO " + TABLE_NAME + " (" + COLUMN_NAME + ","  
                + COLUMN_AGE + ")VALUES(?,?)";   
                 st= mSQLiteDatabase.compileStatement(str);
            } catch (Exception ex) {   
                this.ShowDialog("创建表异常:" + ex.getMessage());   
            }   
             this.InsertData3();   
             this.InsertData4();   
    //         this.InsertData2();   
    //         this.AddData();   
             this.UpdateData();   
            // this.UpdateData2();   
            // this.UpdateData3();   
            // this.DeleteData();   
            // this.DeleteData2();   
            // this.DeleteData3();   
            this.SelectData();   
        }   
      
        @Override  
        protected void onPause() {         
            super.onPause();   
            mSQLiteDatabase.close();// 关闭数据库   
        }   
      
        /**  
         * 插入数据-execSQL  
         */  
        private void InsertData() {   
            try {   
                String str = "INSERT INTO " + TABLE_NAME + " (" + COLUMN_NAME + ","  
                        + COLUMN_AGE + ")VALUES('张三',30)";   
                mSQLiteDatabase.execSQL(str);   
            } catch (Exception ex) {   
                this.ShowDialog("插入数据异常:" + ex.getMessage());   
            }   
      
        }   
      
        /**  
         * 插入数据-execSQL  
         */  
        private void InsertData2() {   
            try {   
                String str = "INSERT INTO " + TABLE_NAME + " (" + COLUMN_NAME + ","  
                        + COLUMN_AGE + ")VALUES(?,?)";   
                Object[] ob = new Object[] { "王五", 50 };   
                mSQLiteDatabase.execSQL(str, ob);   
            } catch (Exception ex) {   
                this.ShowDialog("插入数据异常:" + ex.getMessage());   
            }   
        }   
        /**  
         * 利用statement插入数据-execSQL  
         */  
        private void InsertData3() { 
        	
            try { 
            	
               
               st.bindString(1, "王阳");
               st.bindLong(2, 50);
                st.execute();
                 
                //mSQLiteDatabase.execSQL(str, ob);   
            } catch (Exception ex) {   
                this.ShowDialog("插入数据异常:" + ex.getMessage());   
            }   
        }   
        /**  
         * 利用statement插入数据-execSQL  
         */  
        private void InsertData4() { 
        	
            try { 
            	
               
               st.bindString(1, "周军");
               st.bindLong(2, 33);
                st.execute();
                 
                //mSQLiteDatabase.execSQL(str, ob);   
            } catch (Exception ex) {   
                this.ShowDialog("插入数据异常:" + ex.getMessage());   
            }   
        }   
      
        /**  
         * 插入数据-insert() nullColumnHack,这个参数需要传入一个列名。SQL标准并不允许插入所有列均为空的一行数据,  
         * 所以当传入的initialValues值为空或者为0时  
         * ,用nullColumnHack参数指定的列会被插入值为NULL的数据,然后再将此行插入到表中。  
         */  
        private void AddData() {   
            try {   
                ContentValues cv = new ContentValues();   
                cv.put(COLUMN_NAME, "李四");   
                cv.put(COLUMN_AGE, 40);   
                // long num = mSQLiteDatabase.insert(TABLE_NAME, COLUMN_NAME, cv);   
                long num = mSQLiteDatabase.insertOrThrow(TABLE_NAME, null, cv);   
                this.setTitle("num==" + num);   
            } catch (Exception ex) {   
                this.ShowDialog("插入数据异常:" + ex.getMessage());   
            }   
      
        }   
      
        /**  
         * 更新数据  
         */  
        private void UpdateData() {   
            try {   
                String str = "UPDATE " + TABLE_NAME + " SET " + COLUMN_AGE   
                        + " = 25 WHERE _id=1";   
                mSQLiteDatabase.execSQL(str);   
            } catch (Exception ex) {   
                this.ShowDialog("更新数据异常:" + ex.getMessage());   
            }   
        }   
      
        /**  
         * 更新数据  
         */  
        private void UpdateData2() {   
            try {   
                String str = "UPDATE " + TABLE_NAME + " SET " + COLUMN_AGE   
                        + " = ? WHERE _id=?";   
                Object[] Ob = new Object[] { 33, 2 };   
                mSQLiteDatabase.execSQL(str, Ob);   
            } catch (Exception ex) {   
                this.ShowDialog("更新数据异常:" + ex.getMessage());   
            }   
        }   
      
        /**  
         * 更新数据  
         */  
        private void UpdateData3() {   
            try {   
                ContentValues cv = new ContentValues();   
                cv.put(COLUMN_NAME, "李四4");   
                cv.put(COLUMN_AGE, 43);   
                int num = mSQLiteDatabase.update(TABLE_NAME, cv,   
                        COLUMN_NAME + "=?", new String[] { "李四" });   
                this.setTitle("修改行数num=" + num);   
            } catch (Exception ex) {   
                this.ShowDialog("更新数据异常:" + ex.getMessage());   
            }   
        }   
      
        /**  
         * 删除数据  
         */  
        private void DeleteData() {   
            try {   
                String str = "DELETE FROM " + TABLE_NAME + " WHERE _id=3";   
                mSQLiteDatabase.execSQL(str);   
            } catch (Exception ex) {   
                this.ShowDialog("删除数据异常:" + ex.getMessage());   
            }   
        }   
      
        /**  
         * 删除数据  
         */  
        private void DeleteData2() {   
            try {   
                String str = "DELETE FROM " + TABLE_NAME + " WHERE _id=?";   
                mSQLiteDatabase.execSQL(str, new Object[] { 2 });   
            } catch (Exception ex) {   
                this.ShowDialog("删除数据异常:" + ex.getMessage());   
            }   
        }   
      
        /**  
         * 删除数据  
         */  
        private void DeleteData3() {   
            try {   
                int num = mSQLiteDatabase.delete(TABLE_NAME, "_id=1", null);   
                this.setTitle("删除行数num=" + num);   
            } catch (Exception ex) {   
                this.ShowDialog("删除数据异常:" + ex.getMessage());   
            }   
        }   
      
        /**  
         * 查询数据  
         */  
        private void SelectData() {   
            try {   
                String sql = "SELECT * FROM " + TABLE_NAME;   
                Cursor cursor = mSQLiteDatabase.rawQuery(sql,null);   
                // Cursor cursor = mSQLiteDatabase.query(TABLE_NAME, new String[] {   
                // COLUMN_ID, COLUMN_NAME, COLUMN_AGE }, COLUMN_NAME + "=?",   
                // new String[] { "李四" }, null, null, null);   
                if (cursor != null) {   
                    ListAdapter adapter = new SimpleCursorAdapter(this,   
                            R.layout.list, cursor, new String[] { COLUMN_ID,   
                                    COLUMN_NAME, COLUMN_AGE },   
                            new int[] { R.id.TextView1, R.id.TextView2,   
                                    R.id.TextView3 });   
                    lv.setAdapter(adapter);   
                    
                    tv.setText(Integer.toString(cursor.getCount()));
                  
                }   
            } catch (Exception ex) {   
                this.ShowDialog("查询数据异常:" + ex.getMessage());   
            }   
        }   
        /**  
         * 删除表  
         */  
        private void DropTable(){   
            try{   
                String sql = "DROP TABLE "+TABLE_NAME;   
                mSQLiteDatabase.execSQL(sql);   
            }catch(Exception ex){   
                this.ShowDialog("删除表异常:"+ex.getMessage());   
            }   
        }   
        /**  
         * 删除数据库  
         */  
        private void DropDatabase(){           
            try{   
                this.deleteDatabase(DATABASE_NAME);   
            }catch(Exception ex){   
                this.ShowDialog("删除数据库异常:"+ex.getMessage());   
            }   
        }   
        /**  
         * 提示对话框  
         * @param msg  
         */  
        private void ShowDialog(String msg) {   
            new AlertDialog.Builder(this).setTitle("提示").setMessage(msg)   
                    .setPositiveButton("OK", new DialogInterface.OnClickListener() {   
      
                        @Override  
                        public void onClick(DialogInterface dialog, int which) {   
      
                        }   
      
                    }).show();   
        }   
    }  
    

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  • 原文地址:https://www.cnblogs.com/flyingsir/p/3983767.html
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